[pgpool-committers: 7632] pgpool: Fix copyright.

[Tatsuo Ishii]

Fix copyright.

Pgproto was originally written by me and then contributed to PgPool
Global Development Group in 2018.

Branch
------
master

Details
-------
https://git.postgresql.org/gitweb?p=pgpool2.git;a=commitdiff;h=c4c0adafd6450aa97c848e3ec3a902eecb98dbef

Modified Files
--------------
src/tools/pgproto/buffer.c         | 3 ++-
src/tools/pgproto/extended_query.c | 1 +
src/tools/pgproto/main.c           | 3 ++-
src/tools/pgproto/read.c           | 3 ++-
src/tools/pgproto/send.c           | 3 ++-
5 files changed, 9 insertions(+), 4 deletions(-)